This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Safety Study of Autologous Dendritic Cells Injected Into the Prostate After Cryoablation for Advanced Prostate Cancer (NCT00753220), a na phase 1, phase 2 study. The primary outcome is Maximum Tolerated Dose (MTD).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00753220 |
| Phase | Phase 1, Phase 2 |
| Condition | Prostate Cancer |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 7 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Bostwick Laboratories |
| Results posted | Yes |
2. Clinical Question
Population
The study concerned men with prostatic adenocarcinoma who were chemotherapy-naïve and had limited metastases to lymph nodes and/or bone, as described in the official title. The primary-outcome description refers to metastatic androgen-independent prostate cancer. The registry record does not provide further eligibility details or describe the enrolled participants’ baseline characteristics.
Intervention
The treatment combined cryoablation of the prostate with an intraprostatic injection of VDC2008, the participant’s own immature dendritic cells, and low-dose cyclophosphamide. The recorded VDC2008 dose depended on assigned cohort: 2.5 x 10^7, 7.5 x 10^7, or 1.0 x 10^8 cells. The study description presents the immune treatment as following cryoablation.
Comparator
There was no separate control group. The study is listed as single-group, with allocation recorded as not applicable and no masking. Consequently, the study does not offer a randomized or concurrent comparison of the combined treatment against another treatment or against cryoablation alone.
Primary question
The primary Phase I question was whether a maximum tolerated dose of intratumorally injected VDC2008 could be determined after prostate cryoablation, in the setting of low-dose cyclophosphamide and toxicity monitoring. The registry reports that no participant reached the MTD before the study ended and says additional participants would have been necessary to determine it. A hypothesis of medical benefit appears in the study summary, but the recorded primary outcome was MTD, not a comparative efficacy outcome.
3. Trial Design
This was a Phase I/IIa, single-group study sponsored by Bostwick Laboratories. It enrolled 7 participants and is listed as terminated. The recorded start was 2009-08 and primary completion was 2011-05. The registry record does not state why the study was terminated, so termination should not be attributed to a particular safety, efficacy, recruitment, or operational reason.
The treatment combined prostate cryoablation, intratumoral administration of VDC2008, and low-dose cyclophosphamide. VDC2008 is described as autologous immature dendritic cells. The recorded cell doses varied by assigned cohort: 2.5 x 10^7, 7.5 x 10^7, or 1.0 x 10^8 cells. The intervention description also identifies cyclophosphamide as an oral drug given on an on-and-off schedule, but the registry record does not provide a complete, untruncated treatment description in the information available for this analysis.
There was no separate comparator arm, and masking was listed as none. The registry’s allocation entry is not applicable, consistent with its single-group model. This is therefore not a randomized comparison, and differences between treatment groups cannot be estimated from the study design. The study could describe outcomes among participants receiving the combined regimen, but it could not isolate the contribution of dendritic-cell injection, cryoablation, or cyclophosphamide from the contributions of the other components.
The primary objective focused on determining the maximum tolerated dose of VDC2008 using toxicity and adverse-event monitoring. The recorded timeframe for that outcome was up to 1 year. The study enrolled 7 participants, but the record states that MTD was not reached by any participant before the study ended and that additional participants would have been necessary to determine it. The record lists 1 outcome measure and 0 analyses. It does not report a detailed dose-escalation algorithm, stopping rule, sample-size justification, interim-analysis plan, or statistical analysis plan.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Before assignment: Prior to any screening evaluations, the purpose of the study \& study related tests/procedures will be explained, then subject signs ICF. Subject will undergo screening assessments to determine if he meets all of the inclusion criteria \& none of the exclusion criteria. Screen failures will not be eligible for re-screening.
Overall Study
| Stage | VDC2008 |
|---|---|
| STARTED | 7 |
| COMPLETED | 2 |
| NOT COMPLETED | 5 |
5. Baseline Characteristics
The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.
| Characteristic | Unit | VDC2008 |
|---|---|---|
| Participants analysed | 7 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 2 |
| Age, Categorical: >=65 years | Participants | 5 |
| Age, Continuous | years | 72 (SD 10) |
| Sex: Female, Male: Female | Participants | 0 |
| Sex: Female, Male: Male | Participants | 7 |
| Region of Enrollment: United States | participants | 7 |
6. Primary Endpoint
The registry lists the primary outcome as Maximum Tolerated Dose (MTD), measured over Up to 1 year.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | intratumorally delivered cells |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is titled Maximum Tolerated Dose, with the unit recorded as intratumorally delivered cells and the measure type recorded as a number. In this study, the endpoint concerns identifying the dose of VDC2008 that could be administered following prostate cryoablation in the setting of low-dose cyclophosphamide, while monitoring toxicity and adverse events. The stated timeframe was up to 1 year.
General statistical context: An MTD endpoint is used in early-phase research to characterize dose tolerability and guide decisions about which dose level merits further study. It is not, by itself, a measure of whether a treatment improves a disease outcome. Determining an MTD generally depends on observing enough participants at relevant dose levels and applying specified dose-limiting toxicity criteria and dose-assignment rules. Those criteria and rules are not reported in the registry record, so the exact method planned for identifying the MTD cannot be reconstructed.
The registry reports that MTD was not reached by any study participant before the end of the study and that additional participants would have been necessary to determine it. Thus, the primary endpoint did not yield an established MTD in the posted record. The absence of a reached MTD is not equivalent to a demonstrated absence of dose-related toxicity: it means the record does not report a determined dose threshold under this study’s conduct and monitoring.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The main outcome statement is that the MTD was not reached by any participant before the study ended. The registry explicitly notes that additional participants would have been necessary to determine MTD. The primary outcome therefore remains unresolved in the posted record. This is more informative than simply noting that no MTD value appears: the record itself identifies the need for additional participants as part of the reason a determination was not made.
The study enrolled 7 participants and was terminated. Its recorded primary completion date was 2011-05. The reason for termination is not reported in the registry record. These registry entries establish that the study ended without a recorded MTD determination, but they do not establish why it ended or what dose would have been selected had enrollment continued.
The adverse-event summary lists 7 participants at risk in the VDC2008 group. It records 0 participants affected by serious adverse events and 3 participants affected by other adverse events. These are counts in the registry’s adverse-event summary, not a comparison between treatment arms. The record does not list specific serious adverse-event terms. The death count is not reported in the registry record. The serious-event count should be read as the registry’s recorded count for this group, not as proof that serious harm is impossible or that no unrecorded events occurred.
No comparative efficacy estimate is available from the recorded design and results. The study had no separate control arm, and the registry lists 0 analyses. The study summary includes a hypothesis that the treatment might be medically beneficial, but the primary endpoint was dose tolerability, and no efficacy estimate or analysis is reported in the registry record. It is therefore not possible to quantify a treatment effect or compare the combined regimen with another approach from these results.
No confidence interval, p-value, or other inferential estimate for the primary endpoint is reported in the registry record. Such quantities would describe uncertainty around a defined estimate; they cannot be inferred from the statement that MTD was not reached. With a small enrolled group and no established MTD, the posted result is best interpreted as an incomplete dose-finding outcome, alongside the limited descriptive adverse-event counts. It does not establish a dose for further use, nor does it establish a comparative benefit or a definitive safety profile.
9. Statistical Methods Explained
The record identifies a single-group Phase I/IIa study with no masking and no comparator group. It lists 7 enrolled participants, 1 outcome measure, and 0 analyses. The primary measure is MTD, expressed as a number of intratumorally delivered cells, with a timeframe of up to 1 year. The registry reports a descriptive conclusion about the MTD rather than an estimated dose threshold: MTD was not reached, and additional participants would have been necessary to determine it.
What does a single-group design allow?
General statistical context: A single-group study can describe events observed among people receiving the study regimen. It cannot directly estimate what would have happened to those same participants under a different regimen. Without a concurrent comparison group, observed outcomes may reflect the combined intervention, the underlying condition, other care, or other factors. In this study, cryoablation, VDC2008, and cyclophosphamide were components of the same treatment strategy, so their separate contributions cannot be distinguished from the design alone.
The study is not a randomized comparison. The registry lists allocation as not applicable and the model as single-group. This means there is no basis for a between-arm estimate, and no like-for-like control group against which to interpret adverse events or a disease outcome. The absence of masking is also recorded, but the registry record does not describe whether outcome assessments used standardized procedures or independent review.
How is an MTD endpoint interpreted?
General statistical context: Dose-finding studies use toxicity observations to identify a dose boundary under a prespecified set of rules. The result depends not only on the observed adverse events but also on which doses are tested, how participants are assigned to dose levels, what counts as dose-limiting toxicity, and how the study handles incomplete follow-up. Those design choices determine how evidence from individual participants translates into an MTD estimate.
Here, the record gives three VDC2008 cell-dose levels: 2.5 x 10^7, 7.5 x 10^7, and 1.0 x 10^8, assigned according to cohort. It does not report the dose-escalation procedure, dose-limiting toxicity definition, number of participants treated at each dose, or the decision rule for declaring an MTD. Without those details, readers cannot independently reproduce a dose-finding calculation or assess how the observed toxicities were mapped to dose decisions. The registry’s statement that MTD was not reached is the available result and should not be replaced by a guessed dose threshold.
What do the adverse-event counts describe?
General statistical context: An adverse-event count is a descriptive summary for the participants included in the stated risk group. A count of participants affected is different from a count of event episodes: one person may experience more than one event. The registry excerpt reports participants at risk and participants affected, but does not give event-level detail, timing, severity grades, or causal assessments for the other adverse events. Those details are not reported in the registry record.
For the VDC2008 group, the record lists 7 participants at risk, 0 affected by serious adverse events, and 3 affected by other adverse events. These counts do not provide a control-group rate or an adjusted estimate. The record’s serious-event terms list is empty, and a death count is not reported. The small study size and absence of a comparator limit how broadly these descriptive observations can be interpreted.
What inferential methods are documented?
The registry lists 0 analyses. It does not report a statistical analysis plan, confidence interval, hypothesis test, model, adjustment method, or estimate of treatment effect. Consequently, there is no reported inferential result to interpret for the primary endpoint. General statistical context: A confidence interval expresses uncertainty around a specified estimate, while a hypothesis test assesses data relative to a specified null hypothesis. Both require a defined estimand and analysis; neither can be reconstructed just from a statement that an MTD was not reached.
The registry also includes planning assumptions for sample-size illustrations: a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and effects expressed as fractions of an observed effect. These are described as planning illustrations rather than the trial’s own design. Since this study is single-group and no analyses are listed, those assumptions do not constitute evidence of a prespecified trial analysis or a completed power calculation for this study. No sample-size justification for the trial is reported in the registry record.
General statistical context: Power is a design property tied to a particular effect, outcome, analysis, and sample size; it is not a measure of the probability that a result is true. A planning calculation cannot substitute for an observed estimate, and an observed result cannot be interpreted as having a particular power after the fact. The record does not provide enough trial-specific analysis information to assess power or precision for a comparative effect.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 1 outcome measure and 0 analyses. The primary outcome is MTD. No multiplicity adjustment or hierarchy of additional endpoints is reported in the registry record. The study summary also describes a hypothesis of medical benefit, but the recorded primary outcome is dose tolerability; the summary’s hypothesis should not be treated as a reported efficacy analysis.
General statistical context: Multiplicity arises when several outcomes, time points, subgroups, or hypotheses are assessed. Looking across many potential findings can increase the chance of an apparently notable result occurring by chance. A prespecified testing hierarchy or adjustment can address some of that concern, but no such plan is reported. With no analyses listed, there are no posted hypothesis tests whose multiplicity handling can be evaluated.
The registry record does not report the analysis population, participant flow, exclusions, or handling of missing outcome data. It does not state how participants with incomplete follow-up would have been handled for the MTD assessment, or whether all enrolled participants contributed to every outcome. The adverse-event summary lists 7 participants at risk for the VDC2008 group, but that does not establish the analysis population for outcomes beyond that summary.
General statistical context: Missing observations can affect estimates when the chance that data are unavailable is related to a participant’s condition, treatment, or outcome. Transparent reporting usually distinguishes the number enrolled, treated, followed, and analyzed, and explains any imputation or other missing-data approach. Those details are not reported in the registry record, so the impact of missingness cannot be assessed.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| VDC2008 | 0 | 7 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| VDC2008 | 3 of 7 |
Most frequent non-serious adverse event terms
| Event term | Organ system | VDC2008 |
|---|---|---|
| Memory | Nervous system disorders | 1 of 7 |
| Heartburn | Gastrointestinal disorders | 1 of 7 |
| Fatigue | General disorders | 1 of 7 |
| Pain | General disorders | 1 of 7 |
| Loss of Appetite | Metabolism and nutrition disorders | 1 of 7 |
The registry’s adverse-event summary lists the VDC2008 group with 7 participants at risk. It records 0 participants affected by serious adverse events and 3 participants affected by other adverse events. The event-term list for serious adverse events contains no terms. Deaths are not reported in the registry record.
These are descriptive counts, not evidence from a comparison between groups. No control group was enrolled, so the counts cannot show whether events were more or less frequent than they would have been under another treatment. The registry record also does not provide the specific terms for the other adverse events, event timing, severity grades, relatedness assessments, or a complete account of how adverse events were collected. Those details are not reported in the registry record.
General statistical context: A count of participants affected does not necessarily equal the total number of event episodes, because an individual may experience more than one event. A zero count in a small study describes the observations recorded in that group; it does not establish that the underlying risk is zero. The available counts should therefore be read as limited safety descriptions rather than a definitive characterization of risk.
12. What the Result Does, and Does Not, Mean
The posted record supports a narrow conclusion: the study did not determine an MTD for intratumorally delivered VDC2008. It states that no participant reached MTD before the study ended and that additional participants would have been necessary. This leaves the primary dose-finding question unresolved. The record does not identify a selected MTD or provide enough detail to reconstruct the intended dose-escalation decision process.
The study also reports limited adverse-event counts: 0 participants affected by serious adverse events and 3 affected by other adverse events among 7 at risk in the VDC2008 group. These observations describe the recorded group only. They do not establish a comparative safety advantage, nor do they rule out uncommon or unrecorded harms. Details such as the specific non-serious events and the death count are not reported in the registry record.
The study summary expresses a hypothesis that the combined approach could be medically beneficial, but the primary outcome was MTD and the registry lists 0 analyses. There is no reported comparative efficacy estimate, confidence interval, or p-value. The design also lacks a separate control group. As a result, the posted results do not quantify whether the combined regimen changed a clinical outcome relative to another approach, and they cannot separate the effects of cryoablation, dendritic-cell injection, and cyclophosphamide.
These limitations do not imply that the treatment is ineffective or that it is unsafe. They define what can and cannot be concluded from this registry record. The central reported finding is an incomplete MTD determination, with sparse descriptive safety information and no recorded efficacy analysis. The reason the study was terminated is not reported in the registry record and should not be inferred from the outcome statement.
13. Why This Trial Matters Statistically
This study illustrates why an early-phase dose-finding endpoint must be distinguished from an efficacy endpoint. MTD concerns dose tolerability under a specified monitoring and decision process. Even when a study’s summary describes a hope for medical benefit, that hypothesis is not itself evidence of benefit, and it does not replace the stated primary endpoint.
The record also shows the practical importance of completing a dose-finding design. It reports that MTD was not reached and that additional participants would have been necessary to determine it. Without a dose determination, the primary objective remains open. The record does not provide enough information about dose assignment, toxicity criteria, or stopping rules to judge how the study would have proceeded or what evidence would have been sufficient to declare an MTD.
Statistically, the single-group design makes the scope of interpretation especially important. It can describe observed events in the treated group, but it cannot provide a randomized comparison. The combined regimen also contains multiple components, preventing the observed results from identifying the effect of any one component. The adverse-event summary therefore offers descriptive counts rather than comparative estimates.
Finally, reporting the status of the primary endpoint is meaningful even when no dose estimate results. The registry states plainly that the MTD was not determined and that more participants would have been needed. That distinction prevents an unresolved dose-finding outcome from being mistaken for an established dose or an affirmative efficacy finding. It also makes clear why conclusions should remain limited to what the record documents.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The study enrolled 7 participants, was single-group, and had no separate comparator. The registry lists no masking. These design features limit both the precision of descriptive safety observations and the ability to attribute an outcome to a particular treatment component. Because cryoablation, VDC2008, and cyclophosphamide were combined, the effect of any component cannot be isolated from the posted data.
The MTD was not reached, and the registry states that additional participants would have been necessary to determine it. The reason for termination is not reported in the registry record. The record also does not provide the number treated at each cell-dose level, the dose-escalation algorithm, toxicity thresholds, or dose-limiting event definitions. Those omissions prevent independent reconstruction of the dose-finding process.
The registry lists 0 analyses and does not report confidence intervals, hypothesis tests, or an analysis plan. It does not describe analysis populations, participant flow, missing-data handling, or baseline characteristics. The adverse-event summary gives counts but not specific terms for the other adverse events, event timing, severity grading, causal assessment, or a reported death count. These gaps restrict assessment of both safety detail and outcome completeness.
The official title describes chemotherapy-naïve men with limited metastases to lymph nodes and/or bone, while the primary-outcome description refers to metastatic androgen-independent prostate cancer. The registry record does not clarify how these descriptions relate to the enrolled population. These limitations should be considered alongside the lack of a determined MTD and the absence of a comparative efficacy analysis.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Safety Study of Autologous Dendritic Cells Injected Into the Prostate After Cryoablation for Advanced Prostate Cancer — NCT00753220.
- Registry record last updated 2014-11-04; status last verified 2014-11.
- Results first posted 2014-11-04.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
NCT00753220 is a terminated Phase I/IIa, single-group study sponsored by Bostwick Laboratories. It enrolled 7 participants and evaluated prostate cryoablation followed by intraprostatic VDC2008, autologous immature dendritic cells, with low-dose cyclophosphamide. The listed VDC2008 doses were 2.5 x 10^7, 7.5 x 10^7, or 1.0 x 10^8 cells, depending on assigned cohort.
The primary outcome was MTD, measured as intratumorally delivered cells over up to 1 year. The registry reports that MTD was not reached by any participant before the study ended and that additional participants would have been necessary to determine it. The adverse-event summary lists 0 participants affected by serious adverse events and 3 affected by other adverse events among 7 at risk. No analyses are listed, and no comparator group was included. The reason for termination is not reported in the registry record.